The only sure prevention of termite problems is the use of building materials other than wood. However, if wood is used, there are preventative measures available to the builder other than chemical treatments and treated wood products. A common tree in Austin known to resist termites is the familiar mountain cedar (actually a member of the juniper family). Although not commercially lumbered, natural cedar posts have traditionally been used as foundation piers on old structures, and extensively for fences and furniture. The use of juniper wood has some potential for application as a termite and insect resistant wood.

There is also a bitumen based paint you can paint the bottom of the posts in before you set them in concrete but I can't remember the name of it. They use it a lot on steel to retard rust but I don't think termites like it.

I would suggest cypress but it's termite resistance is only temporary.